Trump’s voter fraud claims test Republican candidates

Mr. Trump has told advisers the issue will help the party win control of Congress next year and win back the White House in 2024. He has privately floated the possibility of an early presidential campaign announcement to underscore the message to conservative voters.

Many Republican candidates have fallen in line. Some have refused to concede defeats from 2020—and, like Mr. Trump, used fraud claims to raise money. Others seeking office have tailored their campaign messages to echo Mr. Trump’s claim that he won to avoid facing a backlash from his supporters.

Still other Republicans, including Glenn Youngkin, who won the Virginia governor’s race earlier this month, have aimed to navigate the issue by sidestepping many of Mr. Trump’s election-fraud claims without disavowing the man himself. Meanwhile, several of the former president’s most persistent Republican critics, such as six-term Rep. Adam Kinzinger of Illinois, have said they aren’t running for re-election.

On the local level, some election chiefs have been harassed and subject to intimidation for refusing to say the vote counting isn’t secure. A wave of election officials and longtime professional staff have left their jobs under pressure.

The message appears to be contributing to eroding confidence in the nation’s election systems—similar to the long-running decline of faith in civic institutions such as the government, the criminal justice system and the media. In October, a Grinnell College poll found that 58% of Americans were very or somewhat confident that the 2022 vote will be counted fairly. Confidence among Republicans was at just 38%, down from 85% in March 2020.

In the wake of last year’s election, Mr. Trump’s campaign and his allies lost dozens of lawsuits around the country that challenged the 2020 results. The Justice Department said there were no signs of widespread fraud. A bipartisan consortium of local, state and federal election officials declared the 2020 race the most secure U.S. election in history.

But Mr. Trump never conceded, and a year later continues to press his case. Last month he sent a letter to The Wall Street Journal editorial board making multiple false claims about the results in Pennsylvania. In a recent interview, he raised doubts about the coming elections. “A lot of people are worried that if we don’t take care of that issue, you’re going to have a problem in ’22 and ’24,” Mr. Trump said. “They don’t want the same thing to happen where the election is rigged. I’m very concerned that the elections are going to be rigged.”

Following his example, some other Republican candidates haven’t conceded their 2020 losses.

In Pennsylvania, Republican Sean Parnell hasn’t conceded in a western Pennsylvania House race he lost last year by 2.3 percentage points—a narrow defeat but more than four times the margin required to trigger an automatic recount in the state. Mr. Trump cited unfounded claims about irregularities in Mr. Parnell’s race when he endorsed the candidate, an author and former Army Ranger, in a crowded…